a. Field of the Invention
The present invention relates generally to automatic watering devices for plants in containers, and, more particularly, to a gravity-actuated automatic watering apparatus that is capable of use with either hanging baskets or planter boxes/pots.
b. Related Art
Both hanging baskets and planter boxes require frequent watering, or else the flowers or other plants therein will quickly wither and die. This is true in moderate as well as hot climates, since such containers hold a relatively small volume of soil and are exposed on all sides, and therefore suffer rapid loss of moisture through evaporation. Moreover, hanging baskets and planter boxes are frequently located under eaves, trees or other features that obstruct or limit their access to rain water.
The need for frequent and routine watering places a significant burden on the homeowner or gardener. The burden is especially difficult for persons who are subject to busy work schedules, as well as for the elderly and persons having limited mobility. Moreover, the situation can become acute if the person is absent for a significant period of time—when away on holiday, for example—unless the person can enlist the temporary services of a neighbor, friend or family member to tend to the watering.
These difficulties have, of course, been well known, and a number of solutions have been proposed over the years. While often effective in the sense of being able to achieve a degree of watering on an automatic basis, none have represented an entirely satisfactory solution.
Certain of these prior devices have relied on electrically-updated valves and controls. This approach has become increasingly common in recent years, however, it remains prohibitively expensive to provide a valve and electric controller for each basket or planter box; moreover, to do so would require running not only a water line but also an electrical cord to each and every planter box and hanging basket. Certain electrically-operated systems have been developed that employ a central controller and valve assembly from which irrigation tubing is routed to individual destinations, however, this means that a multitude of tubes must be routed from their origin (typically, a garage or basement location) to the various plants. Moreover, most such systems employ watering routines that based on some form of a timer. As a result, the container receives water on a periodic basis regardless of whether it is needed. The rates at which hanging baskets and planter boxes lose moisture vary with factors (temperature, humidity, wind speed and so on) that fluctuate tremendously, so that water needs cannot be predicted as a function of time alone; a timer-based system may therefore supply water when it is not needed or vice-versa. The water requirement of different types of plants are often quite specific (some preferring wetter soil and others preferring comparatively dry conditions) and so over-watering and under-watering caused by a timer-based system can be not only wasteful but also potentially catastrophic to the health of the plants. Electronic sensors for determining soil moisture are known, but their potential for use in conjunction with a system for watering hanging baskets and planter boxes is severely restricted by cost and complexity.
Other automatic watering devices have been developed that do not rely on electrical power for their operation and are therefore free from some of the complications noted above. However, a satisfactory solution has remained elusive.
A few such non-electric devices have relied on structures or materials having physical characteristics that respond in some way to changes in moisture—for example, the swelling of a piece of wood—but as a group such mechanisms exhibit poor reliability and long-term durability. Others have been actuated by changes in weight as the amount of water in the container increases/decreases, which offers the prospect of far more reliable operation, however, the mechanisms have generally been deficient for a number of reasons. For example, many of the gravity-operated mechanisms have been excessively complex and/or cumbersome, so that they are too bulky and too expensive to be used with individual hanging baskets or boxes, especially where a yard contains a number of baskets or planter boxes. The bulky, visually obtrusive appearance of many of these devices also renders them unsatisfactory from an aesthetic standpoint. Moreover, many of the mechanically operated devices are intended to operate in conjunction with an associated reservoir (e.g., a small water tank), which is only a partial solution, since the homeowner must replenish the reservoir itself on a periodic basis.
A few devices have been developed that take the more effective approach of controlling the flow of water through small-diameter tubing that can be connected to a tap or other pressure source and strung unobtrusively along an eave or other support. One example is that shown in GB 2,190,573 to Jones: the Jones device is actuated by the weight of a hanging basket, and uses a cylindrical, reciprocating mechanism to control the flow of water through tubing that leads to the plant. The device is admirably compact, but its construction—using comparatively close tolerances and components that must be machined, cast or molded—renders the cost excessively high and also bodes ill for long term reliability in a garden environment, where dirt or debris are likely to accumulate within the interior of the mechanism and impair its operation. Moreover, the Jones device is limited to use with hanging baskets, and has no capacity for use with planter boxes or other containers that are not suspended from an overhanging support. Another example, that shown by U.S. Pat. No. 4,241,538 to Lahr, in some respects represents the converse situation: Lahr employs a simple and reliable mechanism in which the flexible tubing is squeezed between a pair of hinged lever arms beneath a planter box, with the flow being controlled by an adjustable spring mounted between the outer ends of the arms. This device, however, cannot be used with hanging baskets, and moreover, the manner in which it flattens a segment of tubing between the arms renders it somewhat difficult to achieve fine adjustments.
Accordingly, there exists a need for an apparatus for automatically watering plants in containers that is compact and reliable in operation. Furthermore, there exists a need for such an apparatus that operates effectively in conjunction with flexible, small-diameter tubing that can be routed unobtrusively to such containers. Still further, there exists a need for such an apparatus that is capable of being used with both hanging baskets and planter boxes. Still further, there exists a need for such an apparatus that is capable of very fine adjustment. Still further, there exists a need for such an apparatus that is inexpensive to manufacture and that is durable and long-lasting in use.